Check to see that your JS is functioning correctly.
Select the pitch axis,check advanced box and go through a complete movement,full back and full forward,now watch the raw window,does it show the line move from center to top and stay if you pull back and same for push?
If that seems to function properly then it may be a graphical thing,your getting deflection on elevator but it's not showing in the graphics. Now dont get me wrong,I'm not saying that it's a graphics problem! Most likely a JS input issue.